1. Field of the Invention
The present invention relates to an image reading device, an image processing apparatus, and an image reading method.
2. Description of the Related Art
Image reading devices have been known that read a document image by placing a bound document on a document table or the like with a two-page spread facing upward, illuminating a surface to be read of the document from above, and capturing an image of the document. In the image reading devices of this type, some techniques of reducing influence of halation that occurs with a glossy document have been known.
Japanese Laid-open Patent Publication No. 10-327301 discloses an image reading device that reads an image of a document from above by placing the document facing upward on a document table. The image reading device includes first lighting illuminating the document from a first direction, second lighting illuminating the document from a second direction, a charge-coupled device (CCD) sensor shooting an image of the document, and an arithmetic device that turns ON the first lighting and the second lighting sequentially, causes the CCD sensor to shoot images of the document, and calculates reflectance of a document surface from two pieces of obtained image data.
The conventional image reading devices, however, have problems that information acquisition and complicated calculation in order to correct brightness of reflection portions are necessary and much processing time and much memory are required.
Therefore, there is a need for an image reading device, an image processing apparatus, and an image reading method that are capable of reading an image while preventing halation without complicated calculation.